Urusovite is a rare copper aluminum arsenate found primarily in the fumarole deposits of the Tolbachik volcano in Russia. It typically appears as small, delicate tabular or acicular crystals associated with other secondary copper minerals.
Is this urusovite?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch urusovite with a known reference. Urusovite sits at Mohs 4, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: white.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: light green.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: microscopic crystals, platy.
Often confused with
Urusovite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside urusovite
Minerals reported to co-occur with urusovite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- CuAlAsO₅
- Mohs hardness
- 4
- Density
- 3.93 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Microscopic crystals, platy
- Cleavage
- Perfect on {010}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A sublimate at a volcanic fumarole
Where rockhounds find urusovite
Classic worldwide localities
- Second Cinder cone, North Breach of the great fissure Tolbachik eruption, Kamchatka, Russia
Field-hunting tip
Where it forms: A sublimate at a volcanic fumarole. If you start seeing ponomarevite, piypite, sylvite in float, you are in the right ground. Typical habit: microscopic crystals, platy. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify urusovite?+
Where is urusovite found?+
Is urusovite safe to handle?+
What rocks look like urusovite?+
What minerals are found with urusovite?+
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Find urusovite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
